Apparatus for deodorization of animal oils and vegetable oils



June 17, 1947. DEAN 2,422,185

APPARATUS FOR DEODORIZATION OF ANIMAL OILS AND VEGETABLE OILS Filed Aug.20, 1%

33 Jar (kmm INVENTOR 0/0 K. DEA/V ATTORSEY Patented June 17, 1947APPARATUS FOR DEODORIZATION OF ANmAL OILS AND VEGETABLE OILS Dion K.Dean, ltahway, N. J., asslgnor to Foster Wheeler Corporation, New York,N. Y., a corporation of New York Application August 20, 1942, Serial No.455,413

.1 1 This invention relates: generally to the art of refining oils, andmore particularly pertains to an improved process of, and apparatus tor,the continuous deodorization of animal oils and vegetable oils such ascotton seed oil, corn oil, cocoanut oil and the like. The deodorizationoi such oils is mainly for the purpose oi producing certain edibleproducts, although not necessarily limited thereto. by the removal fromthe raw oil oi dissolved air and other undesirable volatile substancesthat would otherwise adversely eifect the product with respect to colorand taste, or cause rapid deterioration.

Heretoiore, the generally accepted method of deodorizing vegetable oilshas been accomplished by the use of the batch system in which a tank isfilled with a charge of cold raw oil, which is thereupon subiected ,tothe desired operating vacuum and then is heated by means of heatingcoiis within the tank, while at the same time stripping steam is forcedthrough the body of 011. By this method, the temperature is graduallybuilt up to the maximum in the presence of vacuum, and consequently someof the volatile constituents including air are released, and escape fromthe oil before it attains its maximum temperature. This is an advantageto th extent that the oil is not highly heated in the presence of oxygenand thus tends to prevent oxidation. However, heating the oil in bulk isa relatively slow process and has the disadvantage that certain otherchemical changes may take place as a result or the extended heatingperiod. Moreover, only the topmost part oi th oil is subjected to fullvacuum since all other portions of the body of oil are under somehydrostatic head. The action of the direct stripp steam will. or course,cause a circulation of the oil and thereby eventually bring allparticles to the top surface, but this takes considerable time, inconsequence of which the deodorization period is undesirably extended,with the adverse results referred to.

Various attempts have been made to make use of a continuous system ofdeodorization by heating the raw oil and then exposing it successivelyin relatively thin layers of large area to sub-atmospheric pressure,while at the same time contacting the oil with stripping steam, with thethought that complete deodorization might thus be brought about in amuch shorter period of time than would be the case with a batch system,thereby minimizing the deleterious chemical reactions produced bysubjecting the body of the oil to a prolonged high temperature heating.Generally, these continuous systems have not 7 Claims. 23-262) provenhighly successful since theyhave lacked the one desirable elementinherent in the batch system. namely, the initial release of the air andcertain undesirable volatile constituents at low temperature. 1

The present invention overcomes the aforementioned disadvantages ofpriorpractice by causing the raw oil which is to be deodorized, to passcontinuously through a preliminary deaerating chamber before beingheated at all, or before being heated to asuiiicient temperature tocause any adverse chemical sheet, to remove a portion ofthe vapors andespecially the air before the oil undergoes the high temperaturetreatment necessary to complete deodorization. with this method. steamconsumption and operating costs are reduced as compared with priormethods, and the size of the apparatus required for carrying out themethod is reduced and the cost thereof is correspondingly less.

For a better understanding of the particular features that characterizethe invention, reference may be had to the following descriptionconsidered in connection with the accompanying drawing, in which thesingle figure is substantially a vertical sectional view illustratingdiagrammatically a preferred form of apparatus for carrying out theprocess of the invention.

Referring to the drawing, the column in comprises a comparatively smalldeaerating section ii and a main deodorizing section i2, the twosections being separated by a division plate or partition It. The rawfeed which may be either cold, or moderately preheated in the heatexchanger H, flows through conduit is to the deaeratin section Ii. Fromthe upper portion of the deaerating section the oil flows downwardlyover a plurality of trays l8, which may be bubble trays although theyare not so illustrated. If desired, stripping steam may be injected intothe lower portion of the deaerating section through steam connection i1.Steam and vapors and non-condensible gases leave the deaerating sectionthrough vapor line I8, and may either flow through the vapor line I 9directly to the barometric condenser 20, or through the vapor line 2| tothe suction end of the thermo-compressor 22, located in the upperportion of the deodorizing section I2. These paths of flow arecontrolled by the valves 23 and 24, and it will be apparent that whenvalve 23 is closed and valve 24 is open the oil in the deaeratingsection will be subjected to a higher vacuum than when the reverse istrue due to the action of the compressor 22. Conduit l9 and its valve 23may be omitted if desired, in

which event the vapors and gases from the deaerating section will passthrough conduit II to the deodorizing section and will be removedtherefrom by the steam Jet 22. Unvaporised oil leaves the deareatingsection through conduit 28 and enters the heater 2| in which the oil isheated to the temperature desired, and then is introduced throughconnection 2'! into the deodorising section, where due to presence of avery high vacuum produced by compressor 22. and the stripping action ofthe steam admitted at II, the remaining undesirable volatileconstituents are released from the oil as it flows downwardly inrelatively thin streams over the bubble tray; 28 to the bottom of thecolumn. The steam and vapors, and non-condensible gases discharged bythe compressor pass through vapor lines 22' and it to the condenserwhere steam and vapors are condensed and properly disposed of, while thenon-condensibie vapors or gases, or both, are withdrawn and eliminatedby a two-stage air pump comprising the inter-condenser Ill and theafter-condenser ii. The finished product is removed from the section l2through conduit I2 by pump it and flows either directly to storagethrough conduits N and 35, or by the proper adjustment of valves II andII, through the tubular heat exchanger II in heat exchange relationshipwith the raw feed, thus utilizing valuable heat that otherwise would belost, although it will be understood that the raw feed should not beheated in excess of a moderate temperature. Check valve 3| prevents theback flow oi any of the finished product. when for any reason the oil inthe bottom of section II falls below the operating level indicamd by thefloat control It. the pump II is shut down. and the valve I, whichadmits operating steam to pump 3!, is closed.

Reference character ll designates generally a boiler or vapor generatorfor a high boiling point liquid such as diphenyi, diphenyl oxide or anequivalent, to be used as a heat transfer agent or a heating medium forthe oil flowing from the deaerating section to the deodorizer, and forsuperheating the stripp steam used in the system. Other heating methodsmay be employed if desired. The boiler ll comprises an upper drum 2 anda lower drum 43 connected by banks of heating tubes l4 and tubes ll.Heat is supplied by burner 46 and the products of combustion, afterbeing directed over the heating surface by bailles 41. enter outlet due48. Vapor from the boiler is conducted by conduits 49 and II to the oilheater 28, and by the conduits l9 and ii to the steam superheater 52.Both of these heaters are of the shell and tube type, and the oil whichflows through the tubes in the heater I6, absorbs heat from the vaporsflowing between said tubes and the shell. The steam entering thesuperheater at II from any suitable source, is superheated in a similarmanner, and is then conducted by the steam line II to the perforateddischarge connection 28 at the bottom of the deodorizer. Ii desired, thesuperheater I! may also be connected by a steam line with the perforatedsteam discharge connection in the deaerating section. The steam flowthrough these lines may be controlled by valves, as indicated at 58,while the flow of vapor to the oil heater 20 and superheater I2 iscontrolled by the valves I8 and II respectively. The vapor that has beencooled or condensed in the heaters is returned to the boiler by theconduits II and Ill and is reheated in a continuous cycle during normaloperation.

4 process and the arrangement of the componentpartsofthesystemwillbereadiiyapparent. Since a considerable volume ofthe air and other volatile constituents will he released from the rawoil, while cold or relatively cool, in the deaerating section H by meansof the vacuum which can be produced therein either by the condenser, orto a greater extent by the compressor, it is obvious that the volume ofvolatiles remainingintheoiitobereieasedwmbesubstantially' reduced, andtherefore the dut and capaci requiredofthemaindeodorinegwillbeles lnconsequence. materially less stripping steam will be required. and thetime during which it would otherwise be necessary to subject the oil tohigh temperature heating will be shortened, thus further preventingundesirable chemical reactions and insuring the product againstoxidation. Additionally, due to the fact that considerably lessstripping steam is used by the deodcriur than would be the case it therewere no preliminary deaeration of the oil, the sine, and therefore thecost of both the compressor and condenser, can be reduced.

Itisto henotedthattheuseofstripplngsteam in the decorating section is ofonly secondary importance. as normall either the moderate vacuum imposedon the oil by the condenser or the high vacuum produced by thecompressor when the valves 28 and 2| are properly adjusted, issufflcient to bring about the desired deaerating eflect as the oil flowsdownwardly from the inlet over the trays I! to the bottom of thesection.

Although an external heater is shown for the oil as it iiows between thed section and thedeodorizer,andalsoanexternalheatexchanger forpreheating the raw feed when desired, it is possible, and might in somecases be a lower portion oi either section.

This application is a continuation-in-part of fggziication Serial No.129,980, filed March 10,

It will be apparent that various other modiilcations maybemadeintheformoftlioapparatus herein disclosed-and in thesteps of themethod herein without departing fromthespiritoftheinventiomwbichisnottobe clilmited excepting by the scopeof theappended Whatisclaimed is:

1. Apparatus for the continuous deodorization of animal or vegetableoils comprising a column, partition mean for dividing the columnintermediate its ends, a deaerating section above said partition means,a deodorizing section below said partition means, means for continuouslyintroducing oil into the upper part of the deaeratins section, means forintroducing steam into the lower part of the deaerating section forcountercurrent contact with the oil introduced therein, means formaintaining a vacuum in the decenting section to cause air to be removedfrom the oil flowing through said section and to be removed from saidsection, a heater, a conduit connected with the lower part or thedeaerating section and with the heater through which 011 is continuouslywithdrawn from the d section and is conducted to the heater, anotherconduit connecting the heater and the upper The numerous advantages ofthis improved part of the deodorizhig section through which heated oilis delivered to the deodorizing section, means for introducing steaminto the lower part of the deodorizing section for counter-currentcontact with the heated oil introduced therein, means for maintaining avacuum in the deodorizing section, and means for continuouslywithdrawing deodorized oil from the deodorizing section.

2. Apparatus for the continuous deodorization of animal or vegetableoils comprising a column, partition means for dividing the columnintermediate its ends, a deaerating section above said partition means,a deodorizing section below said partition means, means for continuouslyintroducing oil into the upper part of the deaerating section, means forintroducing steam into the lower part of the deaerating section forcountercurrent contact with the oil introduced therein, means formaintaining a vacuum in the deaerating section to cause air to beremoved from the oil flowing through said section and to be removed iromsaid section, a heater, a conduit connected with the lower part of thedeaerating section and with the heater through which oil is continuouslywithdrawn from the deaerating section and is conducted to the heater,means ior vaporizing a relatively high boiling point liquid, means forconducting vapor said liquid to said heater for passage therein inindirect heat exchange relationship with the oil therein, anotherconduit connecting the heater and the upper part of the deodorizingsection through which heated oil is delivered to the deodorizingsection, means for introducin steam into the lower part of thedeodorizing section for countercurrent contact with the heated oilintroduced therein, means for maintaining a vacuum in the deodorizingsection, and means for continuously withdrawing deodorized oil from thedeodorizing section.

3. Apparatus for the continuous deodorization of animal or vegetableoils comprising a column, partition means for dividing the columnintermediate its ends, a deaerating section above said partition means,a deodorizing section below said partition means, means for continuouslyintroducing oil into the upper part or the deaerating section, a heater,a conduit connected with the lower part of the deaerating section andwith the heater through which oil is continuously withdrawn from thedeaerating section and is conducted to the heater, another conduitconnectin the heater and the upper part of the deodorizing sectionthrough which heated oil is delivered to the deodorizing section, meansfor introducing steam into the lower part of the deodorizin section forcounter-current contact with the heated oil introduced therein, a steamjet having its suction connected with the upper part of the deodorizingsection, a conduit connecting the upper part oi! the deaerating sectionwith the upper part of the deodorizing section, a. condenser, a conduitconnecting the discharge of the steam jet with the condenser, and means101' continuously withdrawing deodorized oil from the deodorizingsection.

4. Apparatus for the continuous deodorization of animal or vegetableoils comprising a column, partition means for dividing the columnintermediate its ends, a deaerating section above said partition means,a deodorizing section below said partition means, means for continuouslyintroducing oil into the upper part oi. the deaerating section, aheater, a conduit connected with the lower part of the deaeratingsection and with the 6 heater through which oil is continuouslywithdrawn from the deaerating section and is conducted to the heater,means for vaporizing a relatively high boiling point liquid, means forconducting vapor of said liquid to said heater for passage therein inindirect heat exchange relationship with the oil therein, anotherconduit connecting the heater and the upper part of the deodorizingsection through which heated oil is delivered to the deodorizingsection, means for introducing steam into the lower part of thedeodorizing section for counter-current contact with the heated oilintroduced therein, a steam jet having its suction connected with theupper part of the deodorizing section, a conduit conmeeting the upperpart of the deaerating section with the upper part of the deodorizingsection. a condenser, a conduit connecting the discharge of the steamjet with the condenser, and means for continuously withdrawingdeodorized oil from the deodorizing section.

5. Apparatus for the continuous deodorization of animal or vegetableoils comprising a column, partition means for dividing the columnintermediate its ends, a deaerating section above said partition means,a deodorizlng section below said partition means, means for continuouslyintroducing oil into the upper part of the deaeratingsection, a heater,a conduit connected with the lower part of the deaerating section andwith the heater through which oil is continuously withdrawn from thedeaerating section and is conducted to the heater, another conduitconnecting the heater and the upper part of the deodorizing sectionthrough which heated oil is delivered to the deodorizing section, meansfor introducing steam into the lower part of the deodorizing section forcounter-current contact with the heated oil introduced therein, a steamjet having its suction connected with the upper part of the deodorizingsection, a conduit connecting the upper part of the deaerating sectionwith the upper part of the deodorizingsection, a condenser, a conduitfor connecting said conduit between the deaerating anddeodorizing'sections with the condenser, a valve for controlling thelast mentioned conduit, a valve for controlling the conduit between thedeaerating and deodorizing sections, a conduit connecting the dischargeof the steam jet with the condenser, and means for continuouslywithdrawing deodorized oil from the deodorizing section.

6. Apparatus for the continuous deodorization of animal or vegetableoils comprising a column, partition means for dividing the columnintermediate its ends, a deaerating section above said partition means,a deodorizing section below said partition means, means for continuouslyintro-- ducing oil into the upper part of the deaerating section, aheater, a conduit connected with the lower part of the deaeratingsection and with the heater through which 011 is continuously withdrawnfrom the deaerating section and is conducted to the heater, anotherconduit connecting the heater and the upper part of the deodorizingsection through which heated oil is delivered to the deodorizingsection, means for introducing steam into the lower part of thedeodorizing section for counter-current contact with the heated oilintroduced therein, a steam jet having its suction connected with theupper part of the deodorizing section, a conduit connecting the upperpart of the deaerating section with the upper part of the deodorizingsection,

and means for continuously withdrawing deodorized oil from thedeodorizing section.

7. Apparatus for the continuous deodorization 01 animal or vegetableoils comprising a column, partition means for dividing the columnintermediate its ends. a deaerating section above said partition means,a deodorizing section below said partition means, means for continuouslyintroducing oil into the upper part of the deaerating section, a heater.a conduit connected with the lower part 01 the deaerating section andwith the heater through which oil is continuously withdrawn from thedeaerating section and is conducted to the heater, means for vaporizinga relatively high boiling point liquid, means for conducting vapor ofsaid liquid to said heater for passage therein in indirect heat exchangerelationship with the oil therein, another conduit connecting the heaterdeodorizing section through which heated oil is delivered to thedeodorizing section, means for and the upper part of the' 8 introducingsteam into the lower part of the deodorizing section for counter-currentcontact with the heated oil introduced therein. a steam let having itssuction connected with the upper part of the deodorizing section, aconduit connecting the upper part of the deaerating section with theupper part oi the deodorizing section, and means for continuouslywithdrawing deodorized oil from the deodorizing section.

DION K. DEAN.

REFERENCES CITED The foliowing references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,592,112 Lamy-Torrilhon July 13,1926 1,961,211 Graham June 5, 1934 2,000,886 Dow May 7, 1935 2,136,774Hickman Nov. 15. 1938

